The Janefield Colony was established in 1937 by the Department of Mental Hygiene. It provided accommodation and educational instruction to mostly boys and girls aged 14 and over who were classified as 'mentally deficient'. Janefield closed in 1996.

The site of the Janefield Colony was formerly the site of the Janefield Sanitorium, a training farm for tuberculosis patients, run by the Australian Red Cross Society from 1920 to 1933.

The first children were transferred to Janefield from Kew Cottages in 1937.

In 1940, the Director of Mental Hygiene, Dr Catarinich, stated that he envisaged Janefield as a farm colony for 1,000 mental deficients (at that time, it only had accommodation for 150, and only accommodated girls).

Catarinich claimed that the Mental Deficiency Bill would be proclaimed 'as soon as Janefield is sufficiently developed, and directly the public gets to know that the facilities are available, it is certain that we will be swamped with numbers.'

Some children who, having reached the age of 14 and still requiring institutional care, were transferred from the institution at Travancore to Janefield.

A heritage study from 1990 described the originally accommodation at the Janefield Colony thus:

'In 1937 the total accommodation available in the existing buildings - Ward A (later the painters and carpenters shops) and Wards B and C amounted to 100 beds. The two storeyed administrative building, including a flat for the chief nurse and quarters for nurses, and brick ward were occupied in 1939. By 1940 there were 126 patients.'

Construction of a ward for boys commenced in 1940 but was not completed until 1945. By 1955, there were 7 wards at Janefield, and the Colony housed 274 patients.

In 1962, Janefield was proclaimed a Training Centre under the provisions of the Mental Health Act 1959. In 1996, residents of Janefield were transferred to other services for intellectually disabled people.